Internal-combustion engine



Jan. 13, 1931. K 1,788,576

INTERNAL COMBUSTION ENGINE Original Filed Max ch 5, 1926 N I 29 2 5 i;

I".{UNITEDSTATES: T

Patented Jan. 13, 1931 I MARTIN KAHR, or FRANKLIN, rEnNsvLvA'NIA INTERNAL-COMBUSTION Enema Original application filed March 5, 192e, Serial No. 92 ,573. Divided and this application filed. May 14,

This invention relates to. internal combustion engines, and whllev certain features-of the invention are susceptible of embodiment.

in other typesof engines, it has particular (I; reference to oilengines, especially engine's of" the Diesel'or semi-Diesel type. ;While I oil engines embodying the-present invention are capable of a .widegvariety of uses,"ref- I erence' will be made, inorder to illustrate pending application Serial No. 92,573, filed 1o novel features and advantages of the invention, to the particular utility of an; engine of this type in oilfield service,but it is to be expressly understood that'the. invention is not restricted to an engine so employed. Thisapplication is a division-of the co- March 5,1926, by the present applicant.

The type of two-cycle internal combustion engine;hereinicontemplated is what is usually termeda valveless engine and comprises an elongated cylinder with apiston reciprocatively mounted therein; one end of said cylinder forms a, pump-chamber, and the other end --the combustion-chamber.

air orv a mixture of gas and air, is, drawnfrom said combustion-chamber at the end of the. expansion stroke through a piston controlled iport; 1

In the ordinary three-port type of twopumpchamber as well as the by-passing of gas from-the pump chamber-to the cylinder,

and thejexhausting oftheexpanded gases,

are all timed and controlled by the piston itself opening and closing ports in the side walls-of the cylinder, and since theinlet. port to, the pump chamber is not uncovered by the piston until 'near the end of its stroke,

the-in strokeof the piston is opposed by a ro ressivel' increasin vacuum in the b pump chamber; moreover since the time for admission of the charge is short. a full chargecannot ordinarily be obtained. Further losses in efficiency may be caused by a During the operation-of the engine, either for that purpose.

cycle engine, the; admission of gas to. the

restricted area of the inlet port or a speed of they engine that is higher than that-cone,

templated. by the designer of the engine when proportioning'said port, thus produc-. y I a ing a rarefied charge in'gthe pump chainv ber,that' istosay a charge'having less than normal atmospheric pressur e.- hensuch ararefiedcharge is transferred to the combustion chamber, it does not producea complete'scavenging of the products of combustion from said combustion chamber, thuscausing enginep 4-.

It is an object of: the present invention a reduced. power output ;of the to provide an oil enginev of theftwopycle 7 type in which loss ofefliciency dueto high vacuum in the pump chamber, is avoided. More particularly it a is an j object of this invention to-provide an oil engine with means forflimiting the .drop' in pressurein thev pump chamberlduring the intake offlthe air, so as to avoid power-losses and improve the conditions of combustion of the fuel. Other objects will appear as of the invention proceeds, H I

The invention is capable: of receiving a variety of mechanical exp'ressions,, .one. of which has been' shown on the accompanying drawing, but it is to be'expressly understood that the drawing is for purposes of illustration only, and is not to be construed as a definition of the limits of theinvention, reference being had to the appended claims Referring in detail to the drawing,where j in the same reference characters are, employ-- ed' to desig ate corresponding parts n the several figures 'Fig. 1 is an axial section through an en-jg gine cylinder anda portion of the pump chamber-,of an internal combustion engine: embodying the present invention F1g.. 2 isanaxial section through an air valve embodied therein; and o p v I Fig. 3 is a face view of said air valve. Referring firstto Fig. 1, the invention is shown as embodied in an oil engine the cylinder wall of which is designated 20. Said engine is illustrated as providediiwith'the.

usual or any suitable water-jacket 21, and T mounted within the cylinder 20 is theusual lot the description a liner 22 of any suitable construction, the

joint between said cylinder wall and the liner 22 being sealed by a stufling box'23.

WVithin the cylinder is a piston 24 of any suitable construction mounted on the piston rod 25 Said piston is open at its end adjacent the crank shaft and provides with the cylinder casing the usual pump chamber 26 of a two-cycle internal combustion engine.

An air inlet port is indicated at 27 and communicates with the pump chamber 26 through the port 28 in the cylinder wall 20 and the liner 22. A transfer portis shown at 29 and the exhaust conduit is indicated at 30. The inner end of the cylinder is closed by a water-jacketed head 31 of any suitable construction which is interiorly formed to provide a combustion chamber 32.

In conformity with the present invention an auxiliary air valve is provided in'the pump chamber 26 of the engine so asfto prevent an excessive drop in pressure in said chamber during the period when the piston is moving toward the head of the cylinder.

Referring to the drawing, it will be observed that in the absence of any auxiliary air 7 valve the airport 28 will not be opened until the skirt of the piston 24 has uncovered the same. During this stroke of the piston the piston is pulling against a vacuum in the pump chamber which is continuallyincreas ing up to the instantwhen the air port 28 1s uncovered. Hence there is an increasing difference in pressure on the face and the rear of the piston which represents a loss in power. To avoid this loss there is provided an auxiliary air valve which is illustrated at 10 in Fig. 1 and which is shown in detail in Figs. 2 and 3*of the drawing. This auxiliary air valve may be of any suitable construction, and is shown as including a disc 11 of any suitable material which is normally pressed against anapertured wall 12 by means of a plurality, of coiled springs 13. Said springs 13 react between said valve disc 11' and a spring retainer 14 which is mounted on a plurality of bolts 15 which project through, the. apertured wall 12 where they are provided with lock nuts 16. Distance pieces 17 are interposed between the spring retainer 14 and the wall 12. The valve is provided with a. housing-18 of any suitable character, being, shown as having threaded apertures. so that the same may be suitably mounted in the wall in the pump chamber of the cylinder.

The springs 13 are selected of suitable strength so that when a predetermined vacuum, say one pound per square inch, has been created in the pump chamber, said valve disc 11 will open against the tension of said springs and permit the inflow of air into the pump chamber. -This admission of air to the pump chamber before the main air inlet port 28 is opened, possesses opens as soon as a predetermined drop in pressure is produced in the pump chamber,

and further 'airis introduced through the. main air inlet port 28 when the latter is uncovered by the skirt of the piston. During the stroke of the piston in the opposite direction the air thus introduced into the pump chamber is compressed, the escape of air from said chamber being prevented by the closure of the port 28 by the skirt of the piston and by the closure of the valve 10 owing to the internal ressure acting thereon. At the end of t is stroke the air is transferred to the opposite end of the cylin-Z der through the transfer port 29 as is usual in internal combustion engines of the twocycle type, and within said combustion chamber the usual power-developing phases take place. a

It will be seen that-there is herein provided means for avoiding the power lossescaused by high vacuum in the pump chamber, and for securing complete combustion and superior operating efficiency byreason of the uniform full charges of air introduced into the combustion chamber. IVhile the'embodiment of the invention illustrated in the drawinghas been described with consider able particularity, it is to be expressly understood that the invention is not to be restricted to the embodiment shown and described, as various other embodiments will now suggest themselves to those skilled in the art. Reference is therefore to be had to the claims appendedhereto for a definition of the limits of" the invention. I

What is claimed is:

1. In an internal combustion engine, in

combination withthe engine cylinder and pump chamber, apiston in the cylinder, a

main air inlet port for the pump chamber controlled by the movement of the piston, an auxiliary air inlet port communicating with the pump chamber, and a valve controlled only by the pressure in said pump chamber and controlling said auxiliary air inlet port, said valve being adapted to be opened independently of said piston upon a predetermined drop o t-pressure in said pump chamber.

2. In an internal combustion engine, in

- in ane i combination with the engine cylinder, and I 7 pump chamber, a piston in the cylinder a mainair inlet port for the pump chamber controlled by the movement of the piston, an auxiliary air inlet port communlcating with the pump chamber, a Valve member cooperating with said auxiliary air port,

I ating independentlyof the position of said, J piston for opening said auxiliary air inlet 1 in advance ofthe opening of said main air than a predetermined sm and controlled only by the pressure in said pump chamber, and spring means for operating said valve member andyielding upon a predetermined drop of pressure in. said pump chamber and independently of the position of said piston to permit the open- 1 ingof said auxiliary air port.

3. In an internal combustion engine, in combination with the engine cylinder and pump chamber, a piston in the cylinder, 21 main air inlet port for the pump chamber controlled by the'movement of said piston, an auxiliary air inlet port-communicating withjthe pump chamber, and a Valve operinlet. v v

4." In an internal combustion engine in combination with the engine cylinder and pump chamber, a piston in the cylinder,.a mainair inlet port for the pump chamber,

and valve means .in the pump chamber of said engine controlled only by the pressure in said pumpchamber for preventing'more all drop of pressure therein. i

'5. In an internal combustion englne, 1n

combination with the engine cylinder and pump chamber, a piston in the cylinder, a main air inlet port .for the pump chamber opened and closed by said piston, and means in the pumps chamber of said engine con- }trolled only by the pressure thereinfor 'ad- 1 mitting air thereinto for a portion of the stroke of saidpiston and prior to the opening of said main air inlet port.

In testimony whereof I have signed this MARTIN 

